xref: /netbsd/bin/sh/main.c (revision bf9ec67e)
1 /*	$NetBSD: main.c,v 1.41 2001/06/11 01:50:49 wiz Exp $	*/
2 
3 /*-
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kenneth Almquist.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #ifndef lint
41 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\n\
42 	The Regents of the University of California.  All rights reserved.\n");
43 #endif /* not lint */
44 
45 #ifndef lint
46 #if 0
47 static char sccsid[] = "@(#)main.c	8.7 (Berkeley) 7/19/95";
48 #else
49 __RCSID("$NetBSD: main.c,v 1.41 2001/06/11 01:50:49 wiz Exp $");
50 #endif
51 #endif /* not lint */
52 
53 #include <errno.h>
54 #include <stdio.h>
55 #include <signal.h>
56 #include <sys/stat.h>
57 #include <unistd.h>
58 #include <fcntl.h>
59 
60 
61 #include "shell.h"
62 #include "main.h"
63 #include "mail.h"
64 #include "options.h"
65 #include "output.h"
66 #include "parser.h"
67 #include "nodes.h"
68 #include "expand.h"
69 #include "eval.h"
70 #include "jobs.h"
71 #include "input.h"
72 #include "trap.h"
73 #include "var.h"
74 #include "show.h"
75 #include "memalloc.h"
76 #include "error.h"
77 #include "init.h"
78 #include "mystring.h"
79 #include "exec.h"
80 #include "cd.h"
81 
82 #define PROFILE 0
83 
84 int rootpid;
85 int rootshell;
86 STATIC union node *curcmd;
87 STATIC union node *prevcmd;
88 #if PROFILE
89 short profile_buf[16384];
90 extern int etext();
91 #endif
92 
93 STATIC void read_profile __P((const char *));
94 STATIC char *find_dot_file __P((char *));
95 int main __P((int, char **));
96 
97 extern int oexitstatus;
98 /*
99  * Main routine.  We initialize things, parse the arguments, execute
100  * profiles if we're a login shell, and then call cmdloop to execute
101  * commands.  The setjmp call sets up the location to jump to when an
102  * exception occurs.  When an exception occurs the variable "state"
103  * is used to figure out how far we had gotten.
104  */
105 
106 int
107 main(argc, argv)
108 	int argc;
109 	char **argv;
110 {
111 	struct jmploc jmploc;
112 	struct stackmark smark;
113 	volatile int state;
114 	char *shinit;
115 
116 #if PROFILE
117 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
118 #endif
119 	state = 0;
120 	if (setjmp(jmploc.loc)) {
121 		/*
122 		 * When a shell procedure is executed, we raise the
123 		 * exception EXSHELLPROC to clean up before executing
124 		 * the shell procedure.
125 		 */
126 		switch (exception) {
127 		case EXSHELLPROC:
128 			rootpid = getpid();
129 			rootshell = 1;
130 			minusc = NULL;
131 			state = 3;
132 			break;
133 
134 		case EXEXEC:
135 			exitstatus = exerrno;
136 			break;
137 
138 		case EXERROR:
139 			exitstatus = 2;
140 			break;
141 
142 		default:
143 			break;
144 		}
145 
146 		if (exception != EXSHELLPROC) {
147 		    if (state == 0 || iflag == 0 || ! rootshell)
148 			    exitshell(exitstatus);
149 		}
150 		reset();
151 		if (exception == EXINT
152 #if ATTY
153 		 && (! attyset() || equal(termval(), "emacs"))
154 #endif
155 		 ) {
156 			out2c('\n');
157 			flushout(&errout);
158 		}
159 		popstackmark(&smark);
160 		FORCEINTON;				/* enable interrupts */
161 		if (state == 1)
162 			goto state1;
163 		else if (state == 2)
164 			goto state2;
165 		else if (state == 3)
166 			goto state3;
167 		else
168 			goto state4;
169 	}
170 	handler = &jmploc;
171 #ifdef DEBUG
172 	opentrace();
173 	trputs("Shell args:  ");  trargs(argv);
174 #endif
175 	rootpid = getpid();
176 	rootshell = 1;
177 	init();
178 	setstackmark(&smark);
179 	procargs(argc, argv);
180 	if (argv[0] && argv[0][0] == '-') {
181 		state = 1;
182 		read_profile("/etc/profile");
183 state1:
184 		state = 2;
185 		read_profile(".profile");
186 	}
187 state2:
188 	state = 3;
189 	if (getuid() == geteuid() && getgid() == getegid()) {
190 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
191 			state = 3;
192 			read_profile(shinit);
193 		}
194 	}
195 state3:
196 	state = 4;
197 	if (sflag == 0 || minusc) {
198 		static int sigs[] =  {
199 		    SIGINT, SIGQUIT, SIGHUP,
200 #ifdef SIGTSTP
201 		    SIGTSTP,
202 #endif
203 		    SIGPIPE
204 		};
205 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
206 		int i;
207 
208 		for (i = 0; i < SIGSSIZE; i++)
209 		    setsignal(sigs[i]);
210 	}
211 
212 	if (minusc)
213 		evalstring(minusc, 0);
214 
215 	if (sflag || minusc == NULL) {
216 state4:	/* XXX ??? - why isn't this before the "if" statement */
217 		cmdloop(1);
218 	}
219 #if PROFILE
220 	monitor(0);
221 #endif
222 	exitshell(exitstatus);
223 	/* NOTREACHED */
224 }
225 
226 
227 /*
228  * Read and execute commands.  "Top" is nonzero for the top level command
229  * loop; it turns on prompting if the shell is interactive.
230  */
231 
232 void
233 cmdloop(top)
234 	int top;
235 {
236 	union node *n;
237 	struct stackmark smark;
238 	int inter;
239 	int numeof = 0;
240 
241 	TRACE(("cmdloop(%d) called\n", top));
242 	setstackmark(&smark);
243 	for (;;) {
244 		if (pendingsigs)
245 			dotrap();
246 		inter = 0;
247 		if (iflag && top) {
248 			inter++;
249 			showjobs(1);
250 			chkmail(0);
251 			flushout(&output);
252 		}
253 		n = parsecmd(inter);
254 		/* showtree(n); DEBUG */
255 		if (n == NEOF) {
256 			if (!top || numeof >= 50)
257 				break;
258 			if (!stoppedjobs()) {
259 				if (!Iflag)
260 					break;
261 				out2str("\nUse \"exit\" to leave shell.\n");
262 			}
263 			numeof++;
264 		} else if (n != NULL && nflag == 0) {
265 			job_warning = (job_warning == 2) ? 1 : 0;
266 			numeof = 0;
267 			evaltree(n, 0);
268 		}
269 		popstackmark(&smark);
270 		setstackmark(&smark);
271 		if (evalskip == SKIPFILE) {
272 			evalskip = 0;
273 			break;
274 		}
275 	}
276 	popstackmark(&smark);
277 }
278 
279 
280 
281 /*
282  * Read /etc/profile or .profile.  Return on error.
283  */
284 
285 STATIC void
286 read_profile(name)
287 	const char *name;
288 {
289 	int fd;
290 	int xflag_set = 0;
291 	int vflag_set = 0;
292 
293 	INTOFF;
294 	if ((fd = open(name, O_RDONLY)) >= 0)
295 		setinputfd(fd, 1);
296 	INTON;
297 	if (fd < 0)
298 		return;
299 	/* -q turns off -x and -v just when executing init files */
300 	if (qflag)  {
301 	    if (xflag)
302 		    xflag = 0, xflag_set = 1;
303 	    if (vflag)
304 		    vflag = 0, vflag_set = 1;
305 	}
306 	cmdloop(0);
307 	if (qflag)  {
308 	    if (xflag_set)
309 		    xflag = 1;
310 	    if (vflag_set)
311 		    vflag = 1;
312 	}
313 	popfile();
314 }
315 
316 
317 
318 /*
319  * Read a file containing shell functions.
320  */
321 
322 void
323 readcmdfile(name)
324 	char *name;
325 {
326 	int fd;
327 
328 	INTOFF;
329 	if ((fd = open(name, O_RDONLY)) >= 0)
330 		setinputfd(fd, 1);
331 	else
332 		error("Can't open %s", name);
333 	INTON;
334 	cmdloop(0);
335 	popfile();
336 }
337 
338 
339 
340 /*
341  * Take commands from a file.  To be compatible we should do a path
342  * search for the file, which is necessary to find sub-commands.
343  */
344 
345 
346 STATIC char *
347 find_dot_file(basename)
348 	char *basename;
349 {
350 	char *fullname;
351 	const char *path = pathval();
352 	struct stat statb;
353 
354 	/* don't try this for absolute or relative paths */
355 	if (strchr(basename, '/'))
356 		return basename;
357 
358 	while ((fullname = padvance(&path, basename)) != NULL) {
359 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
360 			/*
361 			 * Don't bother freeing here, since it will
362 			 * be freed by the caller.
363 			 */
364 			return fullname;
365 		}
366 		stunalloc(fullname);
367 	}
368 
369 	/* not found in the PATH */
370 	error("%s: not found", basename);
371 	/* NOTREACHED */
372 }
373 
374 int
375 dotcmd(argc, argv)
376 	int argc;
377 	char **argv;
378 {
379 	struct strlist *sp;
380 	exitstatus = 0;
381 
382 	for (sp = cmdenviron; sp ; sp = sp->next)
383 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
384 
385 	if (argc >= 2) {		/* That's what SVR2 does */
386 		char *fullname;
387 		struct stackmark smark;
388 
389 		setstackmark(&smark);
390 		fullname = find_dot_file(argv[1]);
391 		setinputfile(fullname, 1);
392 		commandname = fullname;
393 		cmdloop(0);
394 		popfile();
395 		popstackmark(&smark);
396 	}
397 	return exitstatus;
398 }
399 
400 
401 int
402 exitcmd(argc, argv)
403 	int argc;
404 	char **argv;
405 {
406 	if (stoppedjobs())
407 		return 0;
408 	if (argc > 1)
409 		exitstatus = number(argv[1]);
410 	else
411 		exitstatus = oexitstatus;
412 	exitshell(exitstatus);
413 	/* NOTREACHED */
414 }
415